"We agreed to meet with four (of the striking truck owners) ... as soon as they informed us that the strike had been lifted," Guillermo Campra, a director with the Transport Ministry, told Reuters. "Unfortunately, they decided to protest in this way without first seeking dialogue."

The meeting between the truck owners and the government was scheduled for Feb. 23, Campra said.

Truck owners, who are not unionized in Argentina, went on strike last week in a bid to force the adoption of mandatory minimum grain hauling rates. The work stoppage also slowed the unloading of beans at soyoil and meal manufacturing sites.

The strike had also affected the operation of grain mills in Santa Fe province, where 80 percent of the country´s agricultural exports are processed, transported and loaded onto ships.

"There are no more blockades along the roads of Santa Fe," said Guillermo Wade, manager of the Chamber of Port and Maritime Activity.

Truck drivers appeared to be growing more aggressive on Friday and Argentina's Security Ministry said in a statement 12 truckers had been detained for using "extortionist methods" and "throwing large quantities of grain in the road."

Argentina is the world's top exporter of soybean oil and soymeal and the No. 3 exporter of both corn and soybeans. Some 80 percent of Argentina's agricultural exports depart from Rosario.

(Reporting by Eliana Raszewski; Writing by Dave Sherwood; Editing by Bill Trott and David Gregorio)